However, the UK, for example, can not pass through a Japanese fleet, to unload troops onto a Japanese territory, which would be an act of war. If the UK, or anyone else, is going to make a combat move, they are already at war at the beginning of the turn.
While this makes sense and would be an easy rule to remember it seems to run contrary to the rulebook (or errata or previous ruling) which mentioned that the ‘first’ time you made a combat move against a power with which you weren’t at war you could ignore the presence of an enemy ship in a previous zone. That opens up all kinds of cans of worms, but that is what I recall from reading the book. Has this changed? If so, can someone point me in the direction of the official ruling on this?
Assuming it HAS been changed, then the basic idea is that if you are going to issue a DoW on a Neutral Power, you have to do it by the beginning of Combat Movement and thus can be blocked by picket ships. This would seem to make it harder to hit Pearl with a surprise attack.